Mid-J CO observations of Perseus B1-East 5: evidence for turbulent dissipation via low-velocity shocks

التفاصيل البيبلوغرافية
العنوان: Mid-J CO observations of Perseus B1-East 5: evidence for turbulent dissipation via low-velocity shocks
المؤلفون: Pon, Andy, Johnstone, Doug, Kaufman, Michael J., Caselli, Paola, Plume, René
المصدر: MNRAS 445 (2014) 1508-1520
سنة النشر: 2014
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Astrophysics of Galaxies
الوصف: Giant molecular clouds contain supersonic turbulence and magnetohydrodynamic simulations predict that this turbulence should decay rapidly. Such turbulent dissipation has the potential to create a warm (T ~100 K) gas component within a molecular cloud. We present observations of the CO J = 5-4 and 6-5 transitions, taken with the Herschel Space Observatory, towards the Perseus B1-East 5 region. We combine these new observations with archival measurements of lower rotational transitions and fit photodissociation region models to the data. We show that Perseus B1-E5 has an anomalously large CO J = 6-5 integrated intensity, consistent with a warm gas component existing within the region. This excess emission is consistent with predictions for shock heating due to the dissipation of turbulence in low velocity shocks with the shocks having a volume filling factor of 0.15 per cent. We find that B1-E has a turbulent energy dissipation rate of 3.5 x 10$^{32}$ erg / s and a dissipation time-scale that is only a factor of 3 larger than the flow crossing time-scale.
Comment: 18 pages, 15 figures, 4 tables, accepted by MNRAS, fixed errors described in erratum
نوع الوثيقة: Working Paper
DOI: 10.1093/mnras/stu1856
URL الوصول: http://arxiv.org/abs/1409.2487
رقم الأكسشن: edsarx.1409.2487
قاعدة البيانات: arXiv